Automatic temperature-controlled refrigerating system



E. E. SNADER April 21, 1931.

AUTOMATIC TEMPERATURE CONTROLLED REFRIGERATING SYSTEM Filed March 13, 1929 Attorney L E. 3EME@ @F WHESBE, PENNSYLVANIA ATQMATG TmlERalTURE-NTRQL'LED BEFRIGERTING SYSTEM Application nled .tieren la, Serial Ho. 348,600.

invention relates to an improved automatic temperature controlled relrigerating tor leones, rooms, and analogous enclosures, where two or more units are `led oy one automatic expansion valve as in the cme olf direct expansion systems.

The system disclosed and claimed in this application is also disclosed in application Serial N lll-,726, iiled June 9, 1926, which matured into Patent #1,636,874@ granted t'o me under date of duly 2li, 192'?.

'lhe patent shows, by way of disclosure, the system herein explicitly described and claimed, lout has more particular reference to a particular automatic temperature actuated regulating valve, ol the type also embodied in this present application.

ln nearly all forms of qoa-fetus of this eciiicatiom the distribution or the refrigerant to the expansion coils `or other refrigerating vessels is regulated by hand. Whereas this is practical with machines which always worlr under the same conditions of load and temperature, it has Aoroven to he unsatisfactory in systems olf the type units illustrated.

There are, however, cases, in which, by reason of the variations Ain the conditions of working, a single adjustment does not sulrice. lnstead the man in charge of the machine is compelled to continually adjust the distribution of the refrigerant in order to obtain as lar as possible, the maximum elliciency oil the machine urider these varying conditions.

Refrigeration systems are commonly operated with a substantial loss in. eciency due to the :tact that it is impractical with the systems as at present constructed to control the dow ci the refrigerant meet the varying requirements ci a series of chambers 1oeing refrigerated. A regulating valve is set to maintain the pressure of the refrigerant at such a point necessary to eiect a rapid rostingol all of the coils, the temperature of the refrigerant loeing correspondingly increased 'lhus the cooling eect is lowered, and 'further there is danger .that when the coils have been frosted an objectionable lrosting hack to the compressor will result. @n

the other hand., when me valve is setto supply the refrigerant at a low pressure, the frosting of several coils occurs so slowly that some them remain practically inoperative for a substantial portion of the period or operation.

lt follows, therefore, that ll have evolved and produced a characteristic new type of circulating system and valve arrangement wherein automatic'temperature actuated rerigerant regulating valves are employed and arranged to loe governed by temperature variations in the system, whereby to regulate the flow of refrigerants in accordance with the varying requirements.

@ther ideas, advantages and features oi' the present contribution to the art will loecorne more readily apparent from the follow- 'ing description and the accompanying drawing.

ln the drawing: y

'lhe single gure represents a diagrammatic illustration of the complete system, showing the method of circulation of the refrigerant and the respective placement oi valves.

Referring now to the drawing loy reference numerals, it will loe observed that 25 designates the compressor. 'lhe fluid passes from the compressor through the condenser 26, and into the receiver 27. By way of the piping 28, the lluid passes on to and through the automatic expansion valve A., into the main refrigerant line 23. Located in this refrigerant line is an automatic temperature actuated refrigerant regulatingI valve 29 of the construction illustrated in l atent #1,636,874, already mentioned. This is in direct association with the expansion coil generally designated by the reference numeral 30. lt will he observed that the intake 3l is on one side of the valve 29 and the outlet or discharge end 32 is connected with the main refrigerant line on the opposite side of the valve, alter passing through and having direct co-related con nection with the thermostatic portion of the valve 29.

'lhe reference character v 33 designates a duplicate'hox or extension coil, whose intake end 3l leads from and has communication with the main refrigerant line 23, on the left,

hand side of the second automatic regulating valve 29a.

The discharge end 35 is connected with the feed or refrigerant line on the opposite right hand side of this same valve. The reference character 36 designates the suction which extends back to the compressor 25.

In this system the liquid leaves the receivei` and is led to the expansion valve which is nothing more than a pressure reducing valve where the pressure is reduced from high pressure on the one side to a lower pressure on the other or coil side. Since there is such a little bit of liquid allowed to pass the valve it is quickly vaporized by the heat of the air in the rooms, which results in a lowering temperature in the vicinity of the pipes.

The vapor takes the course shown by the arrows into the bottom of the coil, up through the coil and around through the top of the regulating valve where it comes into contact with the thermostatic element. Now the gas on its way through the coil absorbs the heat of the room. At first the amount of heat absorbed is so great that the temperature of the vapor at the thermostatic element is greater than at the point just after passing the expansion valve, but by passing a continuous stream of cold vapor through the coils in the room, the amount of heat absorbed becomes less and less at the thermostatic element, causing it to contract, allowing the valve to open.

By this system, I am able to control the amount of refrigerant fed to each coil by permitting the refrigerant to do the work, i. e., say the refrigerant after leaving the eXpansion valve is composed or made up of 25 units, the room is warm and requires an expenditure of 5 units to bring it to the required temperature for which my regulating valve has been set, the refrigerant upon going clear through -the coil gives up the five units required and in the case of refrigeration, my refrigerating capacity is reduced by five units. The refrigerant has gone up five units in passing through the coils, which increase in temperature affects my thermostat-or expansion element causing it to exert more pressure on the sliding sleeve and thereby reducing the area through the regulating valve so that the exact amount of refrigerant required to do the work goes through the coils and the remainder of the capacity of twenty five units passes through the regulating valve to the rest of the coils in the series. At the present time, as before stated, hand operated valves are used in this position and require the utmost of attention to maintain correct temperatures in the expansion units or coils.

In carrying out this invention, I wish it distinctly understood that it is not at all necessary to use an automatic temperature conl trol valve ofthe character illustrated and claimed in the patent aforementioned.,

In this type of valve, the thermostat is disposed directly to the temperature of the room or other enclosure within'which it is confined. The gist of this structure is, therefore, the provision of a refrigerating system of the automatic type wherein there is a refrigerant line, a regulating valve in this line, suitable means for controlling the valve, and a byJpass in the form of an expansion or a boX coil, which communicates with the line, at opposite sides of the regulating valve..

Comprehended more specifically, I would emphasize the main refrigerant feed line in connection with the inlet and outlet end of each coil of a series of two or more cooling coils, one automatic temperature regulating valvefor each room and coil, the valve being located in the feed line between the inlet and outlet of the complemental coil and its opening and closing being controlled by the temperature of the refrigerant passing through said complemental coil.

For sake of completeness I desire to mention in conclusion that an automatic cut off spaced valve may be incorporated in the return line, or some well known low pressure or low temperature control for the driving motor may be incorporated in the return line 36 to the compressor.

A careful analysis of the description in connection with the drawings will enable the reader to obtain a clear understanding and comprehension of the features and advantages of the invention, for which reason a more detailed description is regarded as unnecessary.

In conclusion, I desire to remind the reader that minor changes in the shape, size, and rearrangement of details falling Within the scope of the adjoined claims may be resorted to, in actual practice, if desired.

I claim:

l. An automatic refrigeration system comprising condensing mechanism, a refrigerant feed line, an expansion coil having inlet and outlet connections in continuous unobstructed communication with the feed line, an automatic temperature controlled valve interposed in said feed line between and independent of the inlet and outlet connections of said expansion coil to the feed line.

2. In a system as defined in claim 1, said temperature controlled valve being responsive to the temperature of the refrigerant leaving the outlet connection of said coil.

In testimony whereof I aflix my sionature.

EARL E. sNADER. 

